Process of precipitating copper from water.



UNITED STATES PATENT ANDREW J. PoLMETEER, or WHITEHALL, MONTANA,ASSIGNOR OF Two THIRDs TO JOSEPH MITCH AND ALBERTA o. DYGERT, or BUTTE,

MONTANA.

PROCESS OF PRECIPITATING COPPER FROM WAT ER.

SPECIFICATION forming part of Letters Patent No. 699, 009, dated. April29, 1902.

Application filed January 10, 1902.

To aZZ' whom it may concern:

Be it known that I, ANDREW J. POLMETEER,

- bearing geological formations-such, for instance, as the water pumpedfrom coppermines containingcopper sulphate in solution. Thiscopper-water rapidly corrodes and destroys the metal of the pumps andconducting-pipes used in pumping it from mines, and on account of itsdestructive effect it has heretofore been necessary to line the pumpsand conducting-pipes with a non-metallic lining at great expense. Evenwhere such lining is used the copper-water Works through it and attacksand corrodes the metal.

One of the principal purposes of my present invention is to avoid thecorrosion of the pumps and conducting-pipes by neutralizing thecopper-water before it enters the cond ucting-pipes, so that thecopper-water treated according to my invention may be pumped throughordinary metal pipes without injury to the pipes.

The copper-water as pumped from mines or as otherwise issuing from theearth contains in solution copper salts from which the copper has notheretofore been completely recovered. It is the purpose of my inventionto completely precipitate the copper from such salts, as well as fromthose from which the copper has heretofore been recovered, and to thusrecover the full metallic values from the copper-water. I

The particular point of my invention lies in the fact that I treat thecopper-water before it enters the conducting-pipes, precipitating thecopper and at the same time neu- Serial No. 89,117. (No specimens.)

trali zing whatever free acid may be contained in the water, so that theliquid containing the precipitate in suspension enters and passesthrough the pipes of the pumping system without corrosive effect.

In carrying out my invention I employ as a precipitant a liquorcontaining compounds of sulfur and lime, as well as hydrate of lime.This liquor is prepared by boiling sulfur and unslaked lime (OaO) inwater in the proportions of one part of sulfur to four parts of lime,the mixture of sulfur and lime being in the proportion of about twentyounces to a gallon of water. By this process the lime and cium, probablycalcium penta-sulfid (02s,) and calcium thio-sulfate, (CaS O the excessof lime forming calcium hydrate, Ca(OH) In order to form thesecompounds, it is usually necessary to continue the boiling for about onehour, when the liquor is ready for use.

In treating copper-water the precipitant solution is used in differentproportions, varying with the percentage of metallic values contained inthe water. For instance, where the water contains forty-six thousandthsper cent. of metallic values to the ton of the copper-water I useone-half ounce of the precipitant solution to one gallon of the Water tobe treated. The precipitant is simply poured into the copper-waterimmediately before it enters the pipes of the pumping system, and whenused in approximately the proportions stated it precipitates themetallic values in the form of a precipitate, which is readily held insuspension to such an extent that the liquid may be readily pumped fromthe mine. The precipitate contains copper, chiefly in the form of cupricsulfid (OuS) in combination with some oxids of iron and other metalsusually present in the copper-water and a small proportion of oxid ofcopper, (CuO.)

The calcium hydrate of the precipitant neutralizes whatever free acidmay be present in the water, and thus prevents corrosive action on themetal parts of the pumping system. The Water containing the precipitantin suspension is raised to the surface by the pumpsulfur unite to form asoluble sulfid of caling system and discharged into tanks, Where theprecipitate may be permitted to settle or may be separated byfiltration. The precipitate thus obtained may be treated by smelting orin any other suitable manner to recover the metallic copper therefrom.

I do not herein claim the precipitant for copper-water above described,such precipitant forming the subject-matter of an application filed inthe United States Patent Uffice on March 31, 1902, Serial No. 100,865.

Having thus described my invention, what I claim, and desire to secureby Letters Patent, is

1. The herein described process for the treatment of copper-Water, whichconsists in adding to such Water before it enters the pipes of thepumping system, a precipitant solution containing an excess of alkali.

2. The herein-described process of treating copper water, which consistsin adding to such water a precipitant solution containing an excess ofalkali, forcing the water containing the precipitate in suspensionthrough pipes, and subsequently separating the precipitate.

3. The herein-described process of treating copper-water, which consistsin adding to such water before it enters the pipes of the pumpingsystem, a precipitant solution containing a calcium sulfid and an excessof calcium hydrate.

The foregoing specification signed this 3d day of January, 1902.

ANDREW J. POLMETEER.

In presence of- RoY S. ALLEY, EDGAR N. ALLEY.

